Understanding Mercury | #3

As I’ve mentioned, my internship has me looking through data from the MESSENGER mission. In total, around 4,000 orbits were made and for each one of those orbits- there is a plot. Here is an overview of the different regions of the magnetosphere that the plots try and discern:

(Image: American Association for the Advancement of Science)

Within one of the plots I look at, it has a plasma overview, the date, timespan, and orbit number. In the first panel, we see energy, followed by flux, ion counts, and then the three directions of the spacecraft (x,y, and z). In order to gain a deeper understanding of what this plot means I have to look at all six panels. Typically the first region I see is the cusp (dark red in the figure). Then, this is followed by the central plasma sheet and makes up the tail of the magnetosphere. Then, there’s a break. This would be an indicator of the magnetosheath, and a clear indication that we are approaching the next orbit. While the plot might seem simple, often times the characteristics (cusp/plasma sheet) look vastly different each time. This can be determined by the season Mercury is in and which year we are looking. However, the uncertainty makes looking at 4,000 plots fun.